From b05ea3314390e9cb3c27cf2928d48e38fef97050 Mon Sep 17 00:00:00 2001 From: AngeloGioacchino Del Regno Date: Tue, 11 Oct 2022 15:55:48 +0200 Subject: [PATCH] clk: mediatek: clk-mux: Add .determine_rate() callback Since commit 262ca38f4b6e ("clk: Stop forwarding clk_rate_requests to the parent"), the clk_rate_request is .. as the title says, not forwarded anymore to the parent: this produces an issue with the MediaTek clock MUX driver during GPU DVFS on MT8195, but not on MT8192 or others. This is because, differently from others, like MT8192 where all of the clocks in the MFG parents tree are of mtk_mux type, but in the parent tree of MT8195's MFG clock, we have one mtk_mux clock and one (clk framework generic) mux clock, like so: names: mfg_bg3d -> mfg_ck_fast_ref -> top_mfg_core_tmp (or) mfgpll types: mtk_gate -> mux -> mtk_mux (or) mtk_pll To solve this issue and also keep the GPU DVFS clocks code working as expected, wire up a .determine_rate() callback for the mtk_mux ops; for that, the standard clk_mux_determine_rate_flags() was used as it was possible to. This commit was successfully tested on MT6795 Xperia M5, MT8173 Elm, MT8192 Spherion and MT8195 Tomato; no regressions were seen. For the sake of some more documentation about this issue here's the trace of it: [ 12.211587] ------------[ cut here ]------------ [ 12.211589] WARNING: CPU: 6 PID: 78 at drivers/clk/clk.c:1462 clk_core_init_rate_req+0x84/0x90 [ 12.211593] Modules linked in: stp crct10dif_ce mtk_adsp_common llc rfkill snd_sof_xtensa_dsp panfrost(+) sbs_battery cros_ec_lid_angle cros_ec_sensors snd_sof_of cros_ec_sensors_core hid_multitouch cros_usbpd_logger snd_sof gpu_sched snd_sof_utils fuse ipv6 [ 12.211614] CPU: 6 PID: 78 Comm: kworker/u16:2 Tainted: G W 6.0.0-next-20221011+ #58 [ 12.211616] Hardware name: Acer Tomato (rev2) board (DT) [ 12.211617] Workqueue: devfreq_wq devfreq_monitor [ 12.211620] pstate: 40400009 (nZcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--) [ 12.211622] pc : clk_core_init_rate_req+0x84/0x90 [ 12.211625] lr : clk_core_forward_rate_req+0xa4/0xe4 [ 12.211627] sp : ffff80000893b8e0 [ 12.211628] x29: ffff80000893b8e0 x28: ffffdddf92f9b000 x27: ffff46a2c0e8bc05 [ 12.211632] x26: ffff46a2c1041200 x25: 0000000000000000 x24: 00000000173eed80 [ 12.211636] x23: ffff80000893b9c0 x22: ffff80000893b940 x21: 0000000000000000 [ 12.211641] x20: ffff46a2c1039f00 x19: ffff46a2c1039f00 x18: 0000000000000000 [ 12.211645] x17: 0000000000000038 x16: 000000000000d904 x15: 0000000000000003 [ 12.211649] x14: ffffdddf9357ce48 x13: ffffdddf935e71c8 x12: 000000000004803c [ 12.211653] x11: 00000000a867d7ad x10: 00000000a867d7ad x9 : ffffdddf90c28df4 [ 12.211657] x8 : ffffdddf9357a980 x7 : 0000000000000000 x6 : 0000000000000004 [ 12.211661] x5 : ffffffffffffffc8 x4 : 00000000173eed80 x3 : ffff80000893b940 [ 12.211665] x2 : 00000000173eed80 x1 : ffff80000893b940 x0 : 0000000000000000 [ 12.211669] Call trace: [ 12.211670] clk_core_init_rate_req+0x84/0x90 [ 12.211673] clk_core_round_rate_nolock+0xe8/0x10c [ 12.211675] clk_mux_determine_rate_flags+0x174/0x1f0 [ 12.211677] clk_mux_determine_rate+0x1c/0x30 [ 12.211680] clk_core_determine_round_nolock+0x74/0x130 [ 12.211682] clk_core_round_rate_nolock+0x58/0x10c [ 12.211684] clk_core_round_rate_nolock+0xf4/0x10c [ 12.211686] clk_core_set_rate_nolock+0x194/0x2ac [ 12.211688] clk_set_rate+0x40/0x94 [ 12.211691] _opp_config_clk_single+0x38/0xa0 [ 12.211693] _set_opp+0x1b0/0x500 [ 12.211695] dev_pm_opp_set_rate+0x120/0x290 [ 12.211697] panfrost_devfreq_target+0x3c/0x50 [panfrost] [ 12.211705] devfreq_set_target+0x8c/0x2d0 [ 12.211707] devfreq_update_target+0xcc/0xf4 [ 12.211708] devfreq_monitor+0x40/0x1d0 [ 12.211710] process_one_work+0x294/0x664 [ 12.211712] worker_thread+0x7c/0x45c [ 12.211713] kthread+0x104/0x110 [ 12.211716] ret_from_fork+0x10/0x20 [ 12.211718] irq event stamp: 7102 [ 12.211719] hardirqs last enabled at (7101): [] finish_task_switch.isra.0+0xec/0x2f0 [ 12.211723] hardirqs last disabled at (7102): [] el1_dbg+0x24/0x90 [ 12.211726] softirqs last enabled at (6716): [] __do_softirq+0x414/0x588 [ 12.211728] softirqs last disabled at (6507): [] ____do_softirq+0x18/0x24 [ 12.211730] ---[ end trace 0000000000000000 ]--- Fixes: 262ca38f4b6e ("clk: Stop forwarding clk_rate_requests to the parent") Signed-off-by: AngeloGioacchino Del Regno Link: https://lore.kernel.org/r/20221011135548.318323-1-angelogioacchino.delregno@collabora.com Signed-off-by: Stephen Boyd --- drivers/clk/mediatek/clk-mux.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/drivers/clk/mediatek/clk-mux.c b/drivers/clk/mediatek/clk-mux.c index cd5f9fd8cb98..5d217f7377ee 100644 --- a/drivers/clk/mediatek/clk-mux.c +++ b/drivers/clk/mediatek/clk-mux.c @@ -128,9 +128,18 @@ static int mtk_clk_mux_set_parent_setclr_lock(struct clk_hw *hw, u8 index) return 0; } +static int mtk_clk_mux_determine_rate(struct clk_hw *hw, + struct clk_rate_request *req) +{ + struct mtk_clk_mux *mux = to_mtk_clk_mux(hw); + + return clk_mux_determine_rate_flags(hw, req, mux->data->flags); +} + const struct clk_ops mtk_mux_clr_set_upd_ops = { .get_parent = mtk_clk_mux_get_parent, .set_parent = mtk_clk_mux_set_parent_setclr_lock, + .determine_rate = mtk_clk_mux_determine_rate, }; EXPORT_SYMBOL_GPL(mtk_mux_clr_set_upd_ops); @@ -140,6 +149,7 @@ const struct clk_ops mtk_mux_gate_clr_set_upd_ops = { .is_enabled = mtk_clk_mux_is_enabled, .get_parent = mtk_clk_mux_get_parent, .set_parent = mtk_clk_mux_set_parent_setclr_lock, + .determine_rate = mtk_clk_mux_determine_rate, }; EXPORT_SYMBOL_GPL(mtk_mux_gate_clr_set_upd_ops);